4A0-265 Nokia Optical Diagnostics and Troubleshooting Questions and Answers

The available output optical power range is the difference between the maximum gain and the minimum gain range of the ingress amplifier. According to the EPT Power Management Report, the maximum gain is 25.7 dB and the minimum gain range is 14 dB. Therefore, the available output optical power range is 25.7 - 14 = 11.7 dB. To convert this to a logarithmic scale, we use the formula 10^(x/10), where x is the value in dB. Therefore, the available output optical power range in logarithmic scale is 10^(11.7/10) - 10^(14/10) = 14.68 - 25.12 = -0.6 to 1.72dB. References : Nokia Optical Diagnostics and Troubleshooting Course | Nokia, EPT Power Management Report | Nokia

The calculated span loss from Node A to Node B is 10.0 dB. Span loss is the difference between the optical power transmitted and received at two points in a network. It can be calculated by subtracting the received power from the transmitted power. In the exhibit, the transmitted power from Node A to Node B is +7.5 dBm, and the received power at Node B from Node A is -2.5 dBm. Therefore, the span loss is +7.5 dBm - (-2.5 dBm) = 10.0 dB. The other options are incorrect because they do not match the calculation. References: Nokia Optical Diagnostics and Troubleshooting Course, Pluggable Optical Modules: Transceivers for the Cisco ONS Family Data Sheet

When troubleshooting possible generic fiber cuts, the recommended first step is to review alarms at nodes where power loss occurs. This can help identify the location and extent of the fiber cut and the affected services. The next recommended step is to perform network power traces to attempt to determine the point of power loss. Network power traces are graphical representations of the optical power levels along a span or a path. They can be used to compare the measured power levels with the expected power levels and to pinpoint any significant deviations or drops that indicate a fiber cut. The other options are incorrect because they either do not help locate the fiber cut or are not as effective as network power traces. References: Nokia Optical Diagnostics and Troubleshooting Course, OAM and Diagnostics Guide

 A Threshold Crossing Alert (TCA) alarm is a type of alarm that indicates that a monitored parameter has crossed a predefined threshold. For example, a TCA alarm can be triggered when the optical power received at a port is too high or too low. The default severity level for a TCA alarm is warning, which means that it does not affect the service but may require attention. The other severity levels are critical, major, and minor, which indicate different degrees of impact and urgency of the alarms. The severity level of a TCA alarm can be changed by the user using the Nokia 1830 Engineering and Planning Tool (EPT) or the Nokia 1350 Optical Management System (OMS). References: Nokia Optical Diagnostics and Troubleshooting Course, Nokia 1830 PSS-32 and PSS-16 Photonic Service Switch Release 8.0 Alarms and Conditions Reference Guide

A “Loss of Signal” (LOS) alarm is a critical alarm that indicates that there is no or very bad signal at the physical interface. LOS alarm is also raised when the signal level drops below the threshold, at which a high bit error rate (BER) is predicted. LOS alarm can be caused by physical damage, power outage, or misconfiguration of the equipment. LOS alarm can affect the service availability and performance of the optical network. Therefore, it is typically assigned a critical severity level, which means that it requires immediate attention and resolution2. Other severity levels are major, minor, and warning, which indicate different degrees of impact and urgency of the alarms. References: Troubleshooting Guide for Cisco NCS 1002, T1: A Survival Guide, M-series SONET/SDH alarms and troubleshooting tips

The command show interface 1/8/UNEIN detail is used to retrieve the total optical power detected at the ingress interface of a Raman amplifier. This command displays detailed information about the UNEIN interface, which is the unidirectional east input interface of the Raman amplifier. The total optical power detected at the UNEIN interface is shown as Input Power (dBm) in the output of this command1. References : Nokia Optical Diagnostics and Troubleshooting Course | Nokia

The Customer Release Notes (CRNs) document collects documented solved known issues, new issues discovered after the product software has been released, as well as software upgrade procedures and firmware details. This document is useful for troubleshooting because it can help identify if a problem is related to a known issue or a software bug, and if there is a workaround or a solution available. The CRNs also provide information about the software compatibility and interoperability of different Nokia products and platforms. The other options are incorrect because the EPTUG and the UPG do not contain information about known issues, and the CRNs do not provide instructions for automated provisioning, commissioning, and power balancing functions. References: Nokia Optical Diagnostics and Troubleshooting Course, Nokia Optical Diagnostics and Troubleshooting Exam

A passive component in a CDC-F network configuration is the MSH4-FSB Fiber Shuffle Module. This module is used to rearrange the fibers between the CDC-F modules and the wavelength routers, so that each wavelength router can access any of the 96 wavelengths in the C-band. The MSH4-FSB module does not require any power or active components, and it does not perform any optical amplification or switching2. References : Nokia Optical Diagnostics and Troubleshooting Course | Nokia, Nokia 1830 Photonic Service Switch (PSS) | Nokia

The command show interface am2125a 1/6/lineout detail is used to retrieve the total output power level of the AM2125A amplifier module. This command displays detailed information about the lineout interface, including the current optical power, wavelength, and status. The total output power level is shown as Output Power (dBm) in the output of this command1. References : Nokia Optical Diagnostics and Troubleshooting Course | Nokia